This invention relates to a brake booster comprising a housing divided into two chambers by a partition. Each of these chambers include a vacuum chamber of constant pressure and a working chamber of variable pressure which are formed by a first booster piston on the side closest to the brake pedal and a second booster piston on the side closest to the master cylinder, with the vacuum chambers being in permanent mutual connection. Such a brake booster is known from the French Pat. No. 1,537,497.
In the known brake booster, the connection between the two vacuum chambers is provided by the fact that the housing of the brake booster has a larger diameter on the side closest to the master cylinder than on the side closest to the brake pedal. Into the sector of the larger diameter, a cup-shaped cylinder is inserted, the bottom of which forms the partition of the brake booster. An annular chamber is formed between the inserted cup-shaped cylinder and the larger-diameter sector of the housing of the brake booster. This annular chamber enables the vacuum to get from one vacuum chamber to the other vacuum chamber.
The prior known brake booster has the disadvantage that it is relatively complicated in design.
Above all, it is disadvantageous relative to cost that the cup-shaped cylinder has to be held inside the housing of the brake booster by distance members. The mounting of such a cup-shaped cylinder requires considerable expenditure, which raises the costs of the brake booster. The external diameter of the brake booster and the number of the members increase.